Tension between India and China escalated after Chinese troops destroyed the bunker in mid-June.

India said about 100 pilgrims could not cross the border to visit Mount Kailash in Tibet.

New Delhi: China today said it has blocked the entry of Indian pilgrims traveling to Kailash-Mansarovar in Tibet from the Nathu La pass, alleging that Indian troops have crossed the Sikkim border into Chinese territory and demanding their immediate withdrawal. A Chinese government spokesperson said diplomatic protests have been lodged with India both in New Delhi and Beijing. There has been tension at the border after Chinese troops crossed into Indian territory earlier this month and destroyed an old makeshift bunker, leading to a face-off.

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Union Home Secretary Rajiv Mehrishi said on Tuesday that two batches of a total of about 100 pilgrims could not cross the border to visit Mount Kailash in Tibet and returned to Sikkim capital Gangtok. A third batch was not granted visas and did not leave Delhi. About 400 pilgrims travel in batches every year to Kailash-Mansarovar by the Nathu La route and are received across the border by the Chinese.

The first batch of pilgrims reached Nathu La on June 20, when a meeting was scheduled between senior military officers of both sides to discuss the border escalation, but were stalled there for three days before returning as the tension continued.

China has alleged that the bunker it destroyed in remote Doko La, obstructed a road it is is building in its territory. Chinese forces had in November 2008 too destroyed some makeshift Indian army bunkers in Doko La, which is at the Sikkim-Bhutan-Tibet tri-junction.

China had asked Indian authorities to remove the bunker and when India did not agree, got across a bulldozer and destroyed it, sources said. Beijing has been upset at India building new bunkers and upgrading older ones along the border in Sikkim in the last few years to augment its defences against China's People's Liberation Army.

India and China have been unable to resolve their border dispute after the 1962 war. China claims Arunachal Pradesh as South Tibet, and has been told repeatedly by Delhi that the north-eastern state is an integral part of India. Delhi says Beijing has occupied its territory in the Ladakh plateau.

Small incursions are common across the Line of Actual Control, the de facto border that runs some 4,000 km (2,500 miles) across the Himalayas. Both sides have held nearly 20 rounds of border talks since the early 1990s, with little progress.

The Kailash Mansarovar Yatra is of religious and cultural significance for Hindus, Jains and Buddhists. In 2015, China agreed at Prime Minister Narendra Modi's request to let Indians access the mountain, considered the abode of Lord Shiva, through the Nathu La Pass, which is a relatively easier route than through a pass in Uttarakhand.